This invention relates to a method using the drive device of a rod coating station, in which the drive device includes at least a telescopic articulated shaft, at the first end of which is a replaceable grooved rod and at the opposite end of which is the shaft of the drive motor, and in which the rotation of the rod creates an axial force, which is cancelled out by a counterforce brought to the end of the rod at the articulated shaft side. In addition, the invention relates to an arrangement for implementing the method.
U.S. Pat. Nos. 4,889,093 and 5,383,968 disclose rod coating devices suitable for the surface sizing and coating of paper. FIG. 2 of the latter publication shows that, in the device, the coating rod is set in a cradle, which is loaded and pressed shut with the aid of its own loading hoses. The loading hoses are supported on a unified profile rib, which is in turn supported at selected intervals on profiling spindles.
At the rod coating station, the grooved rod set in the cradle is rotated from its end by a special drive device, so that it regulates precisely, in a known manner, the amount of the coating, sizing, or similar substance to be spread on the surface of the wet web.
In accordance with the state of the art, at the end of the rod outside the cradle an end bearing is arranged, which receives the axial driving force caused by the rotation of the rod. The rod extends to the other side of the end bearing, where the end of the rod is fitted into a hole in a known type of attachment head of a telescopic articulated shaft, and is locked on one side by means of an Allen screw. Such an attachment is slightly eccentric and the rod dances"" as it rotates. The opposite end of the articulated shaft is permanently connected to the motor""s drive shaft.
The construction described according to the state of the art has several significant weaknesses in terms of structure and maintenance. Certain types of connection between the rod and the telescopic shaft result in some web breaks. The time for changing the rod at the spreading location is at least 10 minutes, during which at least five different components must be handled. Further, the installation time is increased by the limited rotation of the telescopic articulated shaft and the hydraulic drive motor, which require tools to bring them to the correct position. In the known solutions, there are also several components that wear and require maintenance, such as, for example, the telescopic articulated shaft, the connector sleeve, the shell of the end bearing, and especially the rod""s rather weak support and end bearings. The lack of a bronze or needle bearing means that the telescopic articulated shaft has a short life, while eccentricity can appear in the joint between the application rod and the articulated shaft. Some fitting components may become detached during installation and fall into the machine. The delivery time is also lengthened by the cutting of the application rod to the desired length and machining both of its ends prior to delivery. If problems do not arise, the application rod must be changed on average about once a week.
The invention is intended to create a new type of method for using a rod coating station""s drive device to carry the axial forces induced by the rod, as well as an arrangement according to the method for easily connecting an application rod to the drive device.
The characteristic features of the method for carrying the axial forces, using a drive device of a rod coating station, in which the drive device includes at least a telescopic articulated shaft, at a first end of which there is a changeable grooved rod and at an opposite end of which there is a shaft of a drive motor, and in which rotation of the rod creates an axial force, which is cancelled by a counterforce brought to an end of the rod on the side of the articulated shaft, is characterized in that the said counterforce is brought to the rod through the articulated-shaft from side drive motor side.
The characteristic features of the arrangement using the drive device of a rod coating station, which drive device includes at least a telescopic articulated shaft, at a first end of which are arranged attachment members, to which is fitted a changeable grooved rod, and at an opposite end of which is fitted a shaft of a drive motor, is characterized in that a special quick attachment head, which is arranged to be detachable, is arranged at the end of the rod.
The advantages gained with the aid of the invention include a more reliable connection between the rod and the telescopic shaft, so that the number of web breaks is reduced. In addition, the changing of the rod is substantially accelerated compared to the state of the art. When the rod is being changed, the number of components to be handled is reduced to three. The other features characteristic of the method and arrangement according to the invention appear in the accompanying Claims and other advantages achieved with the invention are stated in greater detail in the description.
These and other features and advantages of the invention will be more fully understood from the following detailed description of the invention taken together with the accompanying drawings.